AU617891B2

AU617891B2 - Composite wear resistant product

Info

Publication number: AU617891B2
Application number: AU44415/89A
Authority: AU
Inventors: Philip Kempe
Original assignee: Mason & Cox Pty Ltd
Current assignee: Mason & Cox Ltd Pty
Priority date: 1988-11-02
Filing date: 1989-11-02
Publication date: 1991-12-05
Anticipated expiration: 2009-11-02
Also published as: AU4441589A

Description

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617891 37513 GEH:PFB COMMONWEALTH OF AUSTRALIA Form Patents Act 1952-1969 COMPLETE

SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int. Class 0 0 t 0 7 0 F4 4 Application Number: Lodged: Complete Application No: Specification Lodged: Published: Priority: Related Art: o B 0

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0 0 4 4 04 4 TO BE COMPLETED BY APPLICANT Name of Applicant: MASON COX PROPRIETARY LIMITED Address of Applicant: 123 HAYWARD AVENUE TORRENSVILLE, STATE OF SOUTH AUSTRALIA, COMMONWEALTH OF

AUSTRALIA

Actual Inventor: PHILIP C. KEMPE Address for Service: Collison Co. 117 King William Street, Adelaide, SOUTH AUSTRALIA Complete Specification for the invention entitled: COMPOSITE WEAR RESISTANT PRODUCT The following statement is a full description of this invention, including the best method of performing it known to us: ;~li COMPOSITE WEAR RESISTANT PRODUCT This invention relates to a wear resistant product, which is suitable for traditional mining applications where wear rates are high and operating conditions are severe, Wear resistant products of metal are known and one known wear resistant metal is manganese steel, However white iron castings are also known to be used, but white iron is extremely brittle and hence is easily fractured. In order to overcome this problem it is known to embed coated steel mesh reinforcement in the white iron castings as taught by Australian Patent No. 469708, and this has proved to be a marketable feature in castings for abrasion resistant surfaces and has enabled in-roads to be made into areas of applications previously the preserve of manganese steel. However, where severe impacts occur along with the abrasive wear the application of such castings Is limited.

It Is also known for a continuous steel backing to be applied to the white iron casting, but this in one known instance requires an intermediate copper strip to be applied between the white iron and the steel backing. However the composite has then to be heated in a furnace to achieve the desired adhesion 9 thus providing a laminated plate. However the size of the laminated product S° 25 so produced is limited by the size of the available heat treatment furnace.

It Is also known to incorporate "cast-in" steel inserts into the white iron castings to facilitate application of fastenings or other attachments.

However it can be seen that none of these known methods result in a satisfactory unit for use in the majority of requirements in the mining industry.

Thus it is an object of this invention to produced a composite wear resistant product which can be produced in the size required depending on the size of the mould which is made to suit the final product.

0 t"7O ~_LI 2a It is a further object to provide a wear resistant product wherein the wear resistant white iron is cast directly onto a steel backing.

It is a further object of this invention to provide a method of producing a wear resistant product.

Thus there is provided according to the invention a method of producing a composite wear resistant product comprising a white iron casting joined to a steel or iron backing, said method including the steps of positioning in a mould at least two steel inserts having protruding locking fingers, casting the 04. white iron over the steel inserts and the protruding locking fingers whereby the •o inserts are metallurgically and mechanically locked to the white iron, and after cooling of the white iron welding the inserts together to form the backing of the o "15 product...

0 00, o 0,: A4V/ II Ir -e r I Thus there is also provided according to the invention a composite wear resistant product, the product comprising a white iron casting supported on a steel backing, the backing providing at least two steel inserts each having a plurality of fingers extending into and locked mechanically and metallurgically into the white iron, the steel inserts being welded together after the white iron has been cast over the fingers of the steel inserts.

In order to more fully describe the invention reference will now be made to the accompanying drawings in which:o oFigure 1 is a cross-sectional view of a portion of the composite wear product, o Figure 2 is a side view of the insert with various fingers omitted in the sake of clarity, and 3 is a plan view of the insert.

As will be seen in Figure 1 of the drawings, each of the inserts 1 comprise a base 2 from which extend a plurality of spaced fingers 3, the fingers in this ooo example being conical and shaped in the form of a fir tree. In carrying out the invention a plurality of the inserts 1 would be positioned in a mould and slightly spaced from each other, the plates being separated by a refractory material so that when the white iron 4 is poured into the mould, the white cast iron will not pass into the crevices between the inserts.

During the pouring of the white cast iron over the fingers of the inserts, the molten white cast iron causes a partial melting of the fingers, particularly at the tips thereof which achieves a partial fusion bonding of the steel inserts to the white iron. As the white iron cools and shrinks, the plates due to their separation allow movement towards each other as the white cast iron contracts. Also this contraction of the white cast iron will cause the white cast iron to firmly grab and adhere to the fingers so assisting in the union of the two materials.

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I i i i As shown in Figure 1 the white cast iron fully embraces the fingers, and after the product has cooled the individual inserts are welded together by a weld so that there is thus provided a continuous steel backing over the whole area of the white case iron.

The material separating the inserts before the white cast iron is poured is preferably a refractory material of the type that does not produce any gassing and does not

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,p 0 00o 0 0) 0 0 e_ Y IVIK Jh Gj~: contaminate the white cast iron in any way. Preferably such a material is a soft plastic material that is pushed into the crevices between adjacent inserts. It is also realised that the steel inserts are cleaned to ensure that there is no scale or other for sign material on the inserts before the pouring of the white cast iron.

It is to be realised that the inserts would be limited in area and volume so that on pouring of the white cast iron there would be no buckling or distortion of each of the inserts, so that on welding of the inserts together a composite laminate is formed without any distortion. As the melting point of the steel inserts is about 1470 degrees C and the white cast iron is poured at a temperature of about 1500 degrees C, there is a partial melting of the surface S 15 of the fingers, particularly at the top thereof and the tips may be fully melted so o that fusion of the two materials occurs.

o Hence it will be seen that very large components can be produced simply by 0 positioning a sufficient number of insert castings and it is to be noted that the 0 20 inserts are to be cast without the requirement of any refractory coating. As o there is fusion bonding between the two materials an intermediate or filler layer of metal is not required as for instance in copper brazing.

o Referring now to Figure 2 each of the pyramidal fingers 7 may be shaped to key into the white cast iron, the fingers having a step 6 similar to the shape of a fir tree, so that on pouring of the white cast iron the two materials are bonded by the fusion and additionally keyed by the shape of the fingers.

Preferably the insert has a base 8 connected to a portion 9 supporting the fingers 10. The base 8 is of lesser area in plan than the portion 9 with the spacing between adjacent inserts providing the area for the inserts to be welded together. In this instance the inset in plan may be square or rectangular and also it may be hexagonal.

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a Li Figure 3 shows an example of a hexagonal insert 11 with spaced conical fingers 12, these also being stepped at 13, with the base 14 of each finger being of greater diameter than the step. It has been found that the hexagonal shape is preferred, for the inserts when welded together produce a stronger and more durable construction.

In the production of the composites after the Inserts have been welded together the composite is heat treated to remove any welding stresses that may exist. While in the above examples it is preferred that the fingers be conical and of fir-tree shape it is to be realised that other shapes may be utilised, such as plan conical, or plan pyramidal, or stepped pyramidal, or other shapes which could have steps or the like to assist in the bonding of the 15 two metals together. *0 /0/ .t i A49*

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?A O il i PlII li Thus there is produced a composite with the desired hardness of the white iron and the toughness of the backing of steel with the two being intimately attached to form a unitary composite.

Although various forms of the invention have been described in some detail it is to be realised that the invention is not to be limited thereto but can include variations and modifications falling within the spirit and scope of the invention.

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Claims

1. A method of producing a composite wear resistant product comprising a white iron casting joined to a steel or iron backing, said method including the t steps of positioning in a mould at least two steel inserts having protruding locking fingers, casting the white iron over the steel inserts and the protruding locking fingers whereby the inserts are metallurgically and mechanically locked to the white iron, and after cooling of the white iron welding the inserts together to form the backing of the product.

2. A method as defined in claim 1 including the step of spacing the inserts with a plastic refractory material to prevent the white iron entering the space between the inserts during the casting of the white iron.

3. A method as defined in claim 1 or claim 2 including the step of shaping the fingers to provide a locking key to the white iron.

4. A composite wear resistant product, the product comprising a white iron casting supported on a steel backing, the backing providing at least two steel inserts each having a plurality of fingers extending into and locked mechanically and metallurgically into the white iron, the steel inserts being welded together after the white iron has been cast over the fingers of the steel inserts. A composite as defined in claim 4 wherein the inserts are spaced from i each other by a plastic refractory material.

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6. A composite as defined in claim 5 wherein each finger tapars towards it outer end, the fingers either being conical or pyramidal in shape.

7. A composite as defined in either claim 5 or claim 6 wherein each finger is stepped in fir tree shape to provide a locking key.

8. A composite wear resistant product substantially as hereinbefore described with reference to the accompanying drawings. MW 7

9. A method of forming a wear resistant product substantially as hereinbefore described with reference to the accompanying drawings. DATED this 26th day of September 1991 MASON COX PROPRIETARY LIMITED By their Patent Attorneys COLLISON CO 0 St 0e 4 e o aol o 4 a a a e~ o t VS LP '3 U "a.